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OK, I see two very different arguments. The technical arguments I understand but the political argument is pretty grim and in my opinion pretty difficult to find agreement on. If 1% is controlling everything a carbon free energy source isn’t going to change that. If LPP makes a breakthrough, the people financing the project own it, not the people that invented it. FF will get absorbed by the 1% as a tool and things will continue. I can’t argue about the one-percent’s influence on our society or if they are a ruling class. I think political movements around the world are expressing their feelings about this but I don’t know if they represent the majority of people. I know in Oakland, CA (live close by) the people are growing increasingly angry with the ‘Take back’ movement and the police. The Port of Oakland takeover seemed to irritate a number of people as the unions were hurt more than the owners. I like the idea of speaking out and keeping greed in check but I don’t know that camping near city hall is accomplishing that. My opinion is people are not involved in government and they need to get more involved. I think that will spur the change in the US. The problem I see is that people are so polarized right now that the people cannot agree. I wish I had an answer but I don’t.

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My problem with ITER is technical. As of a few weeks ago at the burning plasma meeting before the APS Division of Plasma Physics meeting, a member of the ITER team stood up with the latest projections for achieving breakeven. To sustain the plasma temperature, 80 MW of continuous heating is required. The budget does not allow for it so the immediate response was to cut back the diagnostics. How can you gather data when you don’t have diagnostics? The materials issues of ITER are difficult but the scale up to DEMO are nearly impossible. It needs a new wall every few days in some calculations and every month of so otherwise. If DEMO is to be a demonstration power plant how can you operate such a facility cost effectively? Lithium may help some of the first wall problems but I’m not convinced it will fix the problem.

The politics of ITER are daunting and I don’t fault the scientists for the politics. It is a difficult problem politically and in the face of changes in the EU and US I find it amazing that projects like ITER can continue. I hope ITER can succeed but the political problems are growing and the technical issues seem to be cropping up. Even some close to ITER suspect it might only get partly built if built at all.

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I know sodium cooled reactors have far less corrosion problems than water cooled reactors. I think they use a variant of stainless steel to clad the uranium fuel. I personally can’t get behind the idea of liquid salt fuel but I do see the benefits vs. oxide fuel. Something about moving liquid fuel bothers me.

I think casting a wide energy net is a good idea.

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ITER is a risk and the longer it goes on the worse it looks. Unfortunately the wheels are in motion. Most large science like this carries on due to momentum alone but we might have another superconducting super collider (SSC). The SSC was killed suddenly with little warning. ITER might suffer the same fate. I hope it doesn’t for the sake of the scientists that have relocated with their families. I think it is more likely to die a slow death and never reach its real potential. The crown jewel of the ITER program is owned by the Japanese, the International Fusion Materials Irradiation Facility (IFMIF). This facility will be a world class user materials irradiation test facility for the next generation.

The money spent on ITER could be better spent on other project but fusion is at a crossroads as a program. It has been a science program for a long time and people are calling for it to become an energy program. If it becomes an energy program it will die quickly when someone points out that fusion has never produced any net power. I hope the science program continues but opens it’s scope.

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The message is that every energy producing system to date has problems. They have safety that needs to be addressed and we are learning from our mistakes. The mistake at Three Mile Island was a return signal. That was corrected. Chernobyl was a flaw from its design and should never have been built. The USSR had different safety standards than the west. Fukushima started because of a once in two lifetimes event. Errors made after the fact made the situation worse. Why didn’t they design the plant for a 9.0 earthquake and a tsunami? It has to do with risk analysis and cost. All engineered systems have to address these issues as the final product or during production. For example, solar is very clean once the panels are built but building the panels requires toxic chemicals.

I’m not saying that nuclear waste isn’t a problem. In fact it is the biggest problem of fission power. I believe it is a problem within our ability to solve using reprocessing and either fast reactors or particle accelerator driven systems to burn up the waste. There are plenty of systems that can burn the waste and produce energy. If you are asking for a perfect system with no impact it doesn’t exist. Even p-11B will have some by-products that will be undesirable. The one that come to mind of great concern is diborane and other boron containing materials; bad stuff from the chemical side.

The PF can continue to fire after the fuel is expended which is useless but relatively safe. The key questions about a pulse power system are less safety and more about reliability. One might argue that a unreliable power source can cause as many deaths as a power source that produces waste. Imagine losing traffic lights at rush hour because the pulse power failed on a PF. Good news, it produces little waste; bad news, it only works some of the time. I think the pulse power can be overcome but again, like gain from a p-11B fusion reaction, it needs to be demonstrated. I support funding p-11B systems and other fusions systems. If fusion is to be practical, an aneutronic solution is required. The DT reaction produces almost as much waste as a fission plant when you consider the replacement rate of wall materials and other structures.

I know tokamak bashing is popular on this site and I agree that the tokamak is far from ideal, but one should look at the history and compare to the plasma focus. The tokamak is a stable pinch device designed to eliminate the end loss problem of linear pinches (like the plasma focus). Stuff squirts out the ends and the tokamak was supposed to solve it. It sort of solved the problem but introduced new problems. The PF took the other path which is fast pinch devices. Fast pinches have a number of problems which I have mentioned in this thread. They can be solved but the biggest problem remains the net energy problem. I feel safe in saying that those of us that support fission don’t do it because we think it is the best option that could be done, but rather it is the best option we have right now.

Of course, dennisp said the same thing as I’m typing. A thousand curses upon your fast fingers. 🙂

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Tulse wrote: Chernobyl and Fukushima were/are terrible events, but far more people have died from routine coal production.

That said, aneutronic fusion is surely the holy grail of energy production.

I agree 100%. The quest for the holy grail is fraught with challenges.

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Zapkitty…Fission vs. Fusion… This is clearly a personal issue to both of us and I don’t want to argue for the sake of arguing. My bias in this is two parts so I will state them both. First, I am a nuclear engineer. I will always support the development of fission power because I believe it can be a clean power source once certain perceptions about reprocessing are addressed and people are educated. This argument is a similar one to fusion and it has its down falls but I believe it is the faster path to carbon free power at low risk. If you are concerned about risk, ask how many major nuclear accidents have taken place since nuclear power started to produce power. I count 3. One in the US; Three mile island which was a design flaw. Two, Chernobyl. Don’t get me started with that idiocy. Three, Japan. Bad things happened after a very bad situation. I agree that the disaster is ongoing. I agree that siting needs to be better but accidents will only tighten regulations leading to stricter siting requirements. Fission needs to do better and the next generation designs are doing that. So-called Gen III reactors are being built (china, Japan) with Gen IV well into design. Some Gen IV designs have applied for design licenses in the US. The TWR is not that far along yet but a similar idea is being pushed by a US company. They are likely to apply for a license in the next 5 years if the last design exercises pan out. Breeders exist and are licensed to be built in the US but fuel reprocessing is illegal so why build one? A point of interest perhaps, fission cores in nuclear subs last 20 years or more. I don’t know the details, but that is proven technology that could help the TWR concept along should the military declassify the core designs.

My second bias is I actively research plasma focus devices as radiation sources. I am very familiar with LPP and other alternative fusion concepts. I’ve talked to Eric Lerner on a few occasions at meetings. He believes strongly in his work which is true of any serious researcher but his results haven’t gone beyond what other plasma focus devices can do or have done. In fact, the latest LPP yield results were first accomplished in the 1970’s at the 1 MA level. Now do you see my problem? This is not to say that 2012 won’t lead to a revolution at LPP or some other fusion group. My doubts about LPP arise from the nature of the problems they keep having. FoFu-1 is a ~1 MA plasma focus. Pulse power technology at the 1 MA level is straightforward one the time scale (~1 us) for LPP. In fact, two universities in the US have 1 MA drivers that have fewer problems. Sandia National Laboratory has a 1 MA module that can operate at 1 Hz at day long. The lack of pulse power experience at LPP leaves me concerned about the future of the system. Firing a 45 kV capacitor at 40 kV in a ringing circuit will lead to a very short capacitor life (<100 shots in some cases).

Anyway, I guess this is my long way of saying that I disagree with you but I can agree to disagree. Perhaps I lack the foresight to see fusion for what it is; but I ask you to look at the complete history of alternative fusion concepts (non-tokamak or laser driven) and I think you will see they started the same as tokamaks and laser fusion (NIF). It will only take a few more tweaks and we will be there was the common line or more commonly stated “fusion is only ten years away”. Now fusion is 50 years away unless the Chinese invest their GDP in it. ITER will not work because at the latest meeting, it requires 80 MW of continuous heating. NIF has problems with symmetry that may or may not be overcome. FoFu-1 has problems and the ones I know of can be fixed. I hope the problems are fixed and I am proved wrong but I will remain skeptical until I see the data. And until I see fusion gain data, I will not consider fusion as a power source, but what it has been since it’s inception; a concept with a great deal of promise. I will admit that few valuable things are easy, but smart people have worked on the fusion problem for a long time and we still sit without a physics demonstration of fusion in a gain configuration on earth (excluding a nuclear weapon). Even if the physics barriers are overcome, the engineering needs to begin. Fission does not have a physics problem. It has engineering problems and materials problems.

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If FoFu is to work, it will require Gigagauss fields. I don’t know if the filaments are the only way to do it.

The proton measurement technique I referred to measures the fields by deflecting protons using the field. It is a measurement that requires reconstruction but it can be done pretty accurately on paper. The practical reconstruction will be done next year by a group at UC San Diego working with a group at UN-Reno at the ~1MA level. I am optimistic the technique will work with reasonable accuracy. I will see if I can find any papers on it and report back.

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zapkitty wrote:

A high efficiency, low waste fission system is a real threat to the future of fusion. It’s hard to argue against injecting a few neutrons to start an easily sustained chain of reaction.

?

It certainly would not be a threat to aneutronic units… steam and turbines and waste handling eat up any potential savings.

And by the same token any of the smaller neutronic fusion projects such as General or Helion would do as well as the enriched U starter and would be safer to boot.

In my opinion fission breeders would be a power source of last resort… after people realize what the oligarch’s half-assed response to Fukushima is actually doing to Japan [em]any[/em] fission plant is going to have a hard row to hoe no matter how much better it is technically.

Aneutronic fusion should be the first priority and neutronic fusion the second string… and each should be funded accordingly simply because the relative potential payoff of each is worth the investment.

I appreciate that there are more efficient energy conversion systems than steam and turbines but they are and will continue to be the backbone of electricity production for a while. They don’t “eat up” any savings compared to another fission power system. Yes, I am comparing to fission for one reason and one reason alone. Fission power is here and working. The problem of fusion for most folks that work in the power industry is that fusion has yet to produce more electricity than it takes in or even less restrictive, more power generated by the plasma than is required to initiate it.

Fukushima was a disaster without a doubt but it placed a reactor in conditions that it wasn’t designed to operate in or deal with in shutdown. I would argue siting a nuclear power plant is critical and whoever sited it along a coast in a high earthquake area was nuts.

Potential payoff and risk need to be assessed for all these technologies but practicality needs to be mentioned. Fission power works and has worked for over 50 years. Fusion should be the power of tomorrow but we need power now. Even if FoFu or others make a breakthrough tomorrow, it will take a decade to engineer it and start selling electrons. Countries like China and India refuse to wait that long. India is heavily investing in a thorium reactors because they see a path to electricity in less than a decade.

I’m not against fusion or pursuing it but you will not be able to convince people that are interested in the wall plug when fusion hasn’t produced any net power yet. Fission and fusion are on two different levels. Fission is into making it better. Fusion is still in a “we hope, we think and it should”.

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Brian H wrote:

Sorry for the terribly slow reply. I wish I could say I meant the spelling but I R an engineer. 🙂

…

At the top of this screen, click “Your Control Panel”. Then select “Username and Password” on the left margin. Figs the spelunk as decired.

Thanks. Now I R an engineer that can use spell checker.

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I would love to know what they mean by 40X more efficient than conventional reactor designs. A conventional light water reactor is about 27% efficient (thermal to electricity). You can’t be 40 times more efficient than 27%. Mr Carnot does not approve in a thermal sense and neither does the second law of thermodynamics. I hope they mean fuel utilization i.e. burn up which would be a substantial improvement in fission systems. A high efficiency, low waste fission system is a real threat to the future of fusion. It’s hard to argue against injecting a few neutrons to start an easily sustained chain of reaction. Well, nothing is free so time will tell what the real costs (waste, insurance, regulation) really are.

I’ve seen similar systems based upon thorium instead of uranium. If the reactor would burn thorium that would also be a game changer as there is ~100X as much thorium as uranium. Waste is a bit of a problem but the big problems of nuclear waster remediation is the heavy actinides. Thorium cycles are far less likely to produce plutonium which is reason that we don’t reprocess nuclear fuel. “We can’t take the risk that plutonium gets diverted and turned into bombs,” says the gov’t.

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Sorry for the terribly slow reply. I wish I could say I meant the spelling but I R an engineer. 🙂

The papers are listed below.

Ion beam reconstruction from neutron time of flight:
P. Kubes, J. Kravarik, D. Klir, K. Rezac M. Bohata, M. Scholz, M. Paduch, K. Tomaszewski, I. Ivanova-Stanik, L. Karpinski and M. J. Sandowski. “Determination of Deuteron Energy Distribution From Neutron Diagnostics in a Plasma-Focus Device” IEEE Trans. Plasma Sci Vol 37. pp 83-87 2009

Interferometry

Pavel Kubes, Marian Paduch, Tadeusz Pisarczyk, Marek Scholz, Tomasz Chodukowski, Daniel Klir, Jozef Kravarik, Karel Rezac, Irena Ivanova-Stanik, Leslaw Karpinski, Krzysztof Tomaszewski, and Ewa Zieliñska. “Interferometric Study of Pinch Phase in Plasma-Focus Discharge at the Time of Neutron Production” IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 37, NO. 11, NOVEMBER 2009

Optical framing (This is one of my favorite papers with images)

Jos´e Moreno, Patricio Silva and Leopoldo Soto. “Optical observations of the plasma motion in a fast plasma focus operating at 50 J” Plasma Sources Sci. Technol. 12 (2003) 39–45

This short list has references to other diagnostics people have tried. The list can be very extensive. If you really want the best pulsed power diagnostics suite at the moment, you need to look at the Z-diagnostics. The NIF diagnostics are coming along quickly. They are focused on a more difficult problem but they are progressing by leaps and bounds every year.

The FoFu approach….If one is to produce GigaGauss fields something has to happen that does not happen in a conventional plasma focus geometry. The filaments could be key to the FoFu approach. The measurements of magnetic fields in the pinch geometry is challenging but I do know a technique that is being developed base upon the deflection of a high energy proton beam passing through the pinch. I don’t know if the spatial resolution will be enough for the plasmoid but time will tell. I’ll be honest, I am very skeptical. Time will tell.

Glad to hear $50K is not too big in your mind. I think the materials testing could be taken a long way with $50K.

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Brian H wrote: I gather, also, that blades and circlets etc. develop exponential irregularities and erosion patterns. It’s actually very difficult to manage filaments on a single structure with a continuous emitting surface/edge.

Cathode erosion tends to be pretty small or more likely, highly uniform. I have encountered situations when the cathode rods developed a structure along the length (z direction in cylindrical coordinates) near the top of the rods. The structure tended to show up in configurations with just a few rods (<10). I tend to use 14 or more rods of small diameter in my PF. I think the issue is related to the current carried in the rods vs the current carried in the plasma between the rods. The plasma focus video is a bit misleading. The filaments or plasma sheet that travels between the anode and the cathode is not solely connected to the cathode rods. A largely vertical plasma exists in many machines between the rods that returns current while by-passing the cathode rods. My personal opinion is that the rods define the return radius more than carry the current. Some folks have experimented with closed cylinders as cathodes. The yields aren't as good but I don't know the reasons. My personal belief is debris build up in the plasma channel and the requirement to carry all the mass between the electrodes instead of pushing it out radially. I know coaxial plasma accelerators, the axial phase of a plasma focus without radial implosion, use a solid cylinder cathode without any signs of a a specific pattern on the cathode.

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I was under the impression that a plasmoid can form with any atoms so hydrogen atoms could be used. I don’t know of a way to spin the atoms once they ionize to the speeds you desire. The problem with alternating magnetic fields in a plasma is the plasma shields out the fields on a fast time scale which would be required to spin up the plasma. I know that one can spin a plasma up at 100 km/s but beyond that is pretty challenging with any substantial density. Instabilities and power considerations usually limit you. Even if you get the speed you desire, keeping the plasma contained is a problem. Tokamek folks have been working this problem for a long time with little luck. A pinch seems to be the only solution but I am not familiar with the scaling of the plasmoids down to lower current plasma focus or Z-pinch devices.

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Henning wrote:

Given that symmetry in the physical geometry of the electrodes appears to be important, is there any reason that the cathodes have to be separate rods? A solid piece, with projections to guide the plasma filaments, would mean that one never had to worry about individual cathode alignment. Is it necessary to have empty space between the individual cathode rods?

It’s not 100% clear why, but a plasma focus seems to work better with individual cathode rods. People speculate that some of the gas between the anode and the cathode needs to be pushed out while others cite debris as the reason. Groups have employed blades instead of rods that are mounted or welded to a single base piece that helps with alignment. The open area, rod diameter, etc seem to be able to cover a wide range of conditions and still achieve reasonable results. The cathode is not nearly as well studied in PF devices as the anode.

As far as I understood Eric Lerner et al, these rods help the creation of filaments. FoFu creates filaments already in the axial phase. This seems to be different to other DPFs. See also here: https://focusfusion.org/index.php/forums/viewthread/1045/#9674

I don’t know if we are talking about the same thing. The cathode rods, which are prominent in the pictures of the FoFu-1 electrodes, are common in plasma focus devices of the Mather Type. Rods or blades have been used for over twenty years. From my understanding, the initiation of the plasma focus and the tungsten pins near the anode that are installed in the cathode are new to FoFu. I can tell you that my plasma focus uses rods for the cathode and we generate a fairly uniform sheet from visible images. Other plasma focus device observations are similar. The filaments in FoFu-1 could be due to the operating pressure. Most devices even at the 2MA level operate in the 1-10Torr range. FoFu-1 operates at >20 Torr. I remember seeing something like 44 Torr and 80 Torr on some shots. Filaments are more likely to form at neutral high pressure.

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